The present invention relates to a dehumidified/humidified air supply apparatus for keeping the inside of a semiconductor production apparatus, etc., at a fixed humidity.
In order to dehumidify the inside of a semiconductor production apparatus or the like, it has been hitherto adopted that a refrigerating machine is installed directly to a semiconductor production apparatus. The refrigerating machine cools the inside air to a targeted dew point to liquefy and remove moisture from the air, and then circulate the air in the semiconductor production apparatus. The refrigerating machine contains a compressor, a condenser, an evaporator, etc. and thus it has a vibration problem. Further, the condenser needs means for radiating heat to the outside and its construction is complicated. A heat exchanger and an electric heater are required to adjust the humidity of the inside of the semiconductor production apparatus. In addition, means for discharging water which is liquefied and removed for dehumidification and means for supplying water for humidification are needed.
An object of the present invention is to supply a dehumidified/humidified air supply apparatus which is designed in a simple construction, produces little vibration and needs neither supply nor discharge of liquid water.
The present invention provides a dehumidified/humidified air supply apparatus comprising: first and second air passages A, B including heaters 5, 6 disposed at an upstream side thereof, dehumidifier/humidifier 10 having two portions 10a, 10b disposed at a downstream side thereof and a blower 2; driver 17 for moving the dehumidifier/humidifier 10 between the two portions 10a, 10b, connected to the first air passage A carry out moisture desorption to supply humidified air, and the other portion 10b of the dehumidifier/humidifier 10 is subjected to moisture absorption by the air of the second air passage B.
According to the invention, when the air of the first air passage A is heated by the heater 5 at the upstream side of the dehumidifier/humidifier 10, moisture is supplied from the dehumidifier/humidifier 10 into the air, which means that humidified air is supplied in the first air passage A while the moisture absorption is carried out by the dehumidified dehumidifier/humidifier 10 in the second air passage B. On the other hand, when the air of the first air passage A is not heated by the heater 5 at the upstream side of the dehumidifier/humidifier 10, the dehumidifier/humidifier 10 absorbs the moisture in the air, which means the supply of dehumidified air in the first air passage A and also the dehumidification of the dehumidifier/humidifier 10 in the second air passage B by actuating the heater 6 of the second air passage B. The dehumidifier/humidifier 10 is moved between the portion 10a connected to the first air passage A and the portion 10b connected to the second air passage B, by the driver 17.
When the dehumidified air is supplied by the dehumidifier/humidifier 10 as described above, the moisture is removed by the air heated by the heater 6 of the second air passage B, so that no liquid water occurs. When the humidified air is supplied by the dehumidifier/humidifier 10, the moisture is supplied from the second air passage B, so that it is required to supply liquid water. Further, the invention can be achieved with a simple construction containing only the heaters 5, 6 such as an electric heater, the dehumidifier/humidifier 10 and the blower 2, and induce little vibration.
Further, the invention is characterized in that the dehumidified/humidified air supply apparatus is installed to a semiconductor production apparatus having humidity detector 30 therein provided, the semiconductor production apparatus being connected to the first air passage A, through which the air in the semiconductor production apparatus is circulated; and a controller 31 for actuating the heater 5 of the first air passage A and stopping the heater 6 of the second air passage B, when humidity of an inside of the semiconductor production apparatus is lower than a target humidity, and stopping the heater 5 of the first air passage A and actuating the heater 6 of the second air passage B, when the humidity of the inside of the semiconductor production apparatus is higher than the target humidity.
According to the invention, the humidity detector such as a dew point instrument 30 is provided in the semiconductor production apparatus. The air in the semiconductor production apparatus is circulated through the first air passage A. Further, the controller is provided to control as follows. When the humidity of the inside of the semiconductor production apparatus is lower than the target humidity, that is, humidification is needed, the heater 5 of the first air passage A is actuated and the heater 6 of the second air passage B is stopped. Thereby, moisture is supplied from the dehumidifier/humidifier 10 to the first air passage A. Accordingly, humidified air is supplied to the semiconductor production apparatus, while the air in the second air passage B is dehumidified by the dehumidifier/humidifier 10 because the heater 6 is not stopped. Conversely, when the humidity of the inside of the semiconductor production apparatus is higher than the target humidity, that is, dehumidification is needed, the heater 5 of the first air passage A is stopped and the heater 6 of the second air passage B is actuated, thereby the dehumidifier/humidifier 10 absorbs the moisture in the air of the first air passage A, which means the supply of dehumidified air to the semiconductor production apparatus and also the dehumidification of the dehumidifier/humidifier 10 in the second air passage B by actuating the heater 6 of the second air passage B. The dehumidifier/humidifier 10 is moved between the portion 10a connected to the first air passage A and the portion 10b connected to the second air passage B, by the driver 17.
When the dehumidified air is supplied to the semiconductor production apparatus by the dehumidifier/humidifier 10 as described above, the moisture is removed by the air heated by the heater 6 of the second air passage B, so that no liquid water occurs. When the humidified air is supplied to the semiconductor production apparatus by the dehumidifier/humidifier 10, the moisture is supplied from the second air passage B, so that it is required to supply liquid water. Further, the invention can be achieved with a simple construction containing only the heaters 5, 6 such as a electric heater, the dehumidifier/humidifier 10 and the blower 2, and the air in the semiconductor production apparatus is controlled to have the target humidity without inducing significant vibration.
Further, the invention is characterized in that the controller calculates a difference between the humidity of the inside of the semiconductor production apparatus and the target humidity, and in the case where the difference is equal to or less than a predetermined value, controls the heater 5 of the first air passage A or the heater 6 of the second air passage B to operate with a power proportional to the difference.
According to the invention, the controller calculates the difference between the humidity of the inside of the semiconductor production apparatus and the target humidity, and controls the heater 5, 6 of the first air passage A or the second air passage B to operate with a power proportional to the difference when the difference is equal to or lower than the predetermined value, whereby the humidity of the inside of the semiconductor production apparatus is prevented from hunting around the target humidity and it is quickly set to the target humidity. When the difference exceeds the predetermined value, the heater operates with its one hundred percent power.
Further, the invention is characterized in that when the humidity of the inside of the semiconductor production apparatus is lower than the target humidity, the controller calculates a difference between the target humidity and the humidity of the inside of the semiconductor production apparatus, and in the case where the difference is equal to or greater than a predetermined value, the controller controls the air amount of the second air passage B to increase.
According to the invention, when the inside of the semiconductor production apparatus is humidified, the difference between the target humidity and the humidity of the inside of the semiconductor production apparatus is calculated. When the difference is equal to or more than the predetermined value, the amount of the air in the second air passage B is increased. In winter season, the inside of the semiconductor production apparatus is more frequently humidified, and the absolute humidity of the outside air is normally low in winter season. Therefore, when the difference is particularly large, the humidity of the inside of the semiconductor production apparatus can be quickly set to the target humidity by increasing the amount of the air in the second air passage.
Further, the invention is characterized in that the dehumidifier/humidifier includes: a dehumidifying rotor 10 consisting of a substantially cylindrical base member carrying dehumidifying agent thereon, the dehumidifying rotor 10 having a plurality of air passage holes which are designed in a honey-comb structure in an axial direction thereof; a driver 17 for rotating the dehumidifying rotor 10 around a longitudinal axis thereof; and a partition plate 9 which divides the dehumidifying rotor 10 into a first portion 10a and a second portion 10b in a peripheral direction thereof at both ends of the dehumidifying rotor 10 in the axial direction, wherein the first air passage A is connected to the first portion 10a while the second air passage B being connected to the second portion 10b.
According to the invention, the dehumidifier/humidifier has the dehumidifying rotor 10 having a substantially cylindrical overall shape, and the dehumidifying rotor 10 is divided into the first portion 10a and the second portion 10b by the partition plate 9. The first air passage A is connected to the first portion 10a while the second air passage B is connected to the second portion 10b. The dehumidifying rotor 10 is rotated around the axis thereof by the driver 17, so that the it is moved from the first portion 10a to the second portion 10b or from the second portion 10b to the first portion 10a. Accordingly, when the dehumidification is carried out in the first portion 10a and the dehumidified air is supplied from the first air passage A, the dehumidifying rotor 10 at the first portion 10a gradually absorbs moisture and moves to the second portion 10b. At the second portion 10b, the moisture of the dehumidifying rotor 10 is gradually described by the heated air in the second air passage B. Under the state that the dehumidifying rotor 10 is sufficiently dehumidified, it is moved to the first portion 10a again. When the humidification is carried out in the first portion 10a, the moisture of the dehumidifying rotor 10 at the first portion 10a is gradually described by the heated air, and moves to the second portion 10b. At the second portion 10b, the dehumidifying rotor absorbs the moisture of the non-heated air of the second air passage B, and moves to the first portion 10a again under the state that it sufficiently absorbs the moisture. As described above, uniform dehumidified/humidified air is continuously supplied by the substantially cylindrical dehumidifying rotor 10.
Further, the invention is characterized in that the first air passage A and the second air passage B are connected so as to make parallel flow in the dehumidifying rotor 10.
According to the invention, the first air passage A and the second air passage B are connected to the dehumidifying rotor 10 so as to make parallel flow. Accordingly, the blower 2 can be used commonly to the first air passage A and the second air passage B, and the heater 5 of the first air passage A and the heater 6 of the second air passage B can be disposed so as to be adjacent to each other, so that the construction can be simplified.
Further, the invention is characterized in that the first air passage A and the second air passage B are connected so as to make counter flow in the dehumidifying rotor 10.
According to the invention, the first air passage A and the second air passage B are connected to the dehumidifying rotor 10 so as to make the counter flow. Accordingly, the entrance of the second air passage B at which the regeneration of the dehumidifying rotor 10 is most carried out becomes the exit of the first air passage A, and the dehumidification/humidification efficiency can be enhanced.
Further, the invention is characterized in that cooler 21 is provided at the downstream side of the dehumidifier/humidifier 10 connected to the first air passage A.
According to the invention, the cooler 21 is provided at the downstream side of the dehumidifier/humidifier 10 connected to the first air passage A. When the moisture in the air is adsorbed by an adsorpter such as the dehumidifying rotor 10, an exothermic action is induced. When the moisture adsorbed by the dehumidifying rotor 10 is described, an endothermic action is induced. However, since the heater such as the electric heater 5 is provided at the upstream side of the dehumidifier/humidifier such as the dehumidifying rotor 10, the temperature at the exit of the dehumidifying/humidifying apparatus 1 becomes higher than the temperature at the entrance thereof. In order to make the temperature at the exit of the dehumidifying/humidifying apparatus 1 of the first air passage A equal to the temperature at the entrance thereof, the cooler 21 is provided at the downstream side of the dehumidifying rotor 10 connected to the first air passage A. The cooler 21 merely reduces the temperature of the circulated air of the first air passage A, and thus a Peltier cooler which is compact and produces little vibration is preferably used as the cooler.